Replace singleton implementation to support PHP 8 (#276)

composer.json

@@ -30,7 +30,6 @@
         "beberlei/assert": "^3.0",
         "clue/graph": "^0.9.2",
         "doctrine/inflector": "^2.0.3",
-        "florianwolters/component-util-singleton": "^0.3.2",
         "graphp/algorithms": "^0.8.2",
         "hanneskod/classtools": "^1.2",
         "ondram/ci-detector": "^4.0",

src-tests/ConfigProviderTest.php

@@ -138,4 +138,12 @@ public function testShouldFailIfSettingCustomConfigurationOptionsAfterFirstInsta
         // This should fail, as the Config instance was already created
         $config->setCustomConfigurationOptions(['CUSTOM_OPTION']);
     }
+
+    public function testShouldAlwaysGetTheSameSingletonInstance(): void
+    {
+        $firstInstance = ConfigProvider::getInstance();
+        $secondInstance = ConfigProvider::getInstance();
+
+        $this->assertSame($firstInstance, $secondInstance);
+    }
 }

src/ConfigProvider.php

@@ -4,13 +4,11 @@
 
 use Doctrine\Inflector\InflectorFactory;
 use Doctrine\Inflector\Language;
-use FlorianWolters\Component\Util\Singleton\SingletonTrait;
 
 /**
  * Provide access to global configuration (from within the tests).
  * The configuration is immutable - ie. cannot be altered after it is used for the first time.
  *
- * @method static ConfigProvider getInstance()
  * @property-read string $browserName
  * @property-read string $env
  * @property-read string $serverUrl
@@ -21,13 +19,27 @@
  */
 class ConfigProvider
 {
-    use SingletonTrait;
+    /** @var ConfigProvider */
+    private static $instance;
 
     /** @var array Configuration options and theirs values */
     private $config;
     /** @var array Array of custom configuration options that should be added to the default ones */
     private $customConfigurationOptions = [];
 
+    final protected function __construct()
+    {
+    }
+
+    public static function getInstance(): self
+    {
+        if (self::$instance === null) {
+            self::$instance = new static();
+        }
+
+        return self::$instance;
+    }
+
     public function __get(string $name)
     {
         $this->initialize();
@@ -133,4 +145,18 @@ private function retrieveConfigurationValues(array $options): array
 
         return $outputValues;
     }
+
+    /**
+     * Prevent cloning of the singleton
+     */
+    private function __clone()
+    {
+    }
+
+    /**
+     * Prevent unserializing the singleton
+     */
+    private function __wakeup(): void
+    {
+    }
 }